Your doctors may not have memorized dosage information, interactions, and side effects for every drug—but they don't need to, thanks to Epocrates's easy-to-use drug-reference program for mobiles and laptops. The program allows medical professionals to make smart prescribing decisions with the click of a button, and 45% of U.S. doctors have already signed on. "When they are in front of patients, they can get information in a split second," says Rose Crane, the company's CEO. Last year, Epocrates said that it's developing a platform to give doctors access to patients' electronic health records, supplying them with even more instant grist for making sound treatment recommendations.